Fluid expansible passage seal



July 15 1958 o. E. ANDRUs FLUID ExPANsIBLE PASSAGE SEAL Filed Dec. 16,1954 INVENTOR. Orrin E.Andrus BY @MQW , 5 RAN.

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ATTORNEYS.

United States Patent O f' FLUID EXPANSIBLE PASSAGE SEAL rrin E. Andrus,Milwaukee, Wis., assigner to A. 0. Smith Corporation, Milwaukee, Wis., acorporation of New York Application December 16, 1954, Serial No.475,618

4 Claims. (Cl. 10S- 202) This invention relates to a seal for closingthe passage about an object within a casing and more particularly tosuch a seal between a submersible motor-pump unit and the well casing.

In the past, when the well casing has been employed as the dischargepipe, the seal between the pump and the well casing has involvedmechanically-actuated expansible devices or an expansible memberconnected by tubing to a fluid source above the well. The seals of theprior art are quite complicated and consequently are often expensive.

An expansible seal is disclosed in Patent No. 2,623,473 issued toPankratz on December 30, 1952, for a Swab for Tapered Casing or Tubing.The disclosure of Patent No. 2,623,473 employs mechanically-actuatedvalves to inflate a packer with a gas which is normally confined in achamber lowered into the well with the swab. Mechanically-actuatedvalves are also employed to deflate the packer. The gas is admitted tothe tube or drained from the tube by jarring the mechanism to therebyactuate valves by remote means.

According to the present invention, admission and escape of the gas toand from an expansive sealing tube is controlled by a heat-disruptableseal disposed within outlet passages leading from a gas chamber disposedadjacent the seal. One of the outlet passages permits the gas to expandinto the sealing tube and thereby to inflate the tube, while a secondoutlet passage allows the gas to escape to the exterior of the chamberand thereby to deflate the tube.

As applied to a submersible motor-pump assembly, an expansibledoughnut-shaped member or tube encircles the motor-pump and is loweredinto the well therewith. A gas chamber is secured to the assembly orassociated equipment. The chamber is provided with a pair of outletpassages, each being closed by a heat-disruptable material. An electricheating element is disposed adjacent the heat-disruptable material ineach passage and is connected by an electrical cable to a source ofcurrent outside the well. The energization of the heating element fromthe source of current is controlled externally of the well.

After the submersible motor-pump assembly is lowered into the wellcasing to the desired depth, the rst or tube expanding passage is openedby energization of the first heating element. The gas expands and inatesthe tube to seal the submersible motor-pump assembly within the wellcasing. The water is pumped upwardly above the seal and trapped withinthe well casing which acts as the discharge tubing. When the pump is tobe removed, as for repair or replacement, the second passage is openedby energization of the second heating element. The gas escapes from thetube and the tube deflates allowing the motor-pump to 'be removed fromthe well casing.

An object of the present invention is to provide a passage seal which isremotely controlled and also which is positive in action and low in`cost of construction.

The drawing furnished herewith illustrates the best n 2,843,052 PatentedJuly 15, 1958 mode presently contemplated for carrying out theinvention.

In the drawing:

Figure 1 is an elevational view of a well pump and motor unit supportedwithin a well casing;

Fig. 2 is an enlarged View, in cross section, of a preferred embodimentof the sealing and releasing system;

Fig. 3 is a View taken on line 3--3 of Fig. 2; and

Fig. 4 is an enlarged sectional view of a sealed joint employed in theillustrated embodiment of the invention.

Referring to Figure l, there is illustrated a submersible motor-pumpunit of the conventional deep-well variety having a submersible motor 1connected below and in spaced vertical relation to a pump 2 with ascreened water inlet 3 therebetween. The motor-pump unit is supportedwithin a well casing 4 with the water inlet 3 below the level of thewell liquid 5, and with a power line 6 for the motor 1 extendingupwardly along a groove in the motor-pump housing and out of the wellcasing to a conventional starting and operating switch 7 which isconnected to the alternating current supply lines 8. To support themotorpump unit in position, a cable 9 is secured to an eyelet 1t) whichis secured to the motorpump unit and to an eyelet 11 which is attachedto a. casing head 12 closing the top of the well casing 4. The eyelet 11has a shank 13 which is welded to the casing head 12 as at 14.

The casing head 12 is secured as by bolts 15 to a casing flange 16 atthe top of the casing 4 with an O-ring seal 17 therebetween to preventleakage of the well liquid. A discharge pipe 18 is secured within aferrule 19 on the casing head 12 and has a conventional control valve 20to open and close the pipe 18.

To employ the well casing 4 above the motor-pump `unit as a liquidconduit, a generally doughnut-shaped expansible member or tube 21encircles an annular extension 22 of the motor-pump housing and wheninflated prevents the ow of liquid between the motor-pump unit and thewell casing. The water 5 is pumped upwardly and out of the dischargepipe 18 with the well casing 4 replacing the conventional tubingconnecting a discharge pipe to an outlet of the pump. Further, the pumpunit has a check valve, not shown in the drawing, which allows the flowof liquid through the pump 2 only in an upward or outlet direction.

The annular extension 22 is formed integrally with the housing of themotor pump and is centrally indented as at 23 to accommodate thedoughnut-shaped tube 21.

The doughnut-shaped tube 21 is constructed of a ilexible material toallow expansion and contraction of the tube. A suitable material fortube Z1 is a reinforced impervious rubber of a composition similar tothat used in inner tubes of automobile tires. The rubber beingimpervious to gases remains inflated until positively released.

Referring in particular to Fig. 2, the tube 21 is provided with a stem24 to eifect an inflation and deflation of the tube Z1. The stem 24extends through an aperture in the annular extension 22 and is connectedinto cornmunication with a gas chamber 25 by a conduit 26 to effect theinflation of the tube 21.

As more clearly shown in Fig. 4, the conduit 26 passes through athreaded cap Z7 and is sealed within the stem 24 by threading the capupon an enlarged threaded portion 28 of the stem 24. The' adjacent edgesof the openings in the cap 27 and the stem 24 through which the conduit26 passes are chamfered as at 29 and 3i), respectively, to provide arecess adjacent the conduit 26. A ring seal 31 having an axial half-mooncross-section is disposed within the recess, as shown, and when the cap27 is threaded onto the enlarged portion 28, the ring seal 31 tightlyseals the conduit 26 within the stem 24.

As more clearly shown in Figs. 2 and 3, the gas chamber 2S is secured tothe top of the pump 2 by a threaded portion 32 extending from thechamber and threaded into a` correspondingly threaded aperture in thepump 2. The chamber 25 is provided with a recessed side 33 in alignmentwith the indented portion 23 of the annular extension 22 to maintain apassage of constant cross-section past the chamber. A pair of spacedtubular extensions or outlets 34 and 35 are formed integrally with thechamber to form a pair of outlet passages. A fluid 36 is confined underhigh pressure within the chamber. Nitrogen or argon, which are inertgases, are desirable as the confined fluid although other fluids may beemployed.

The conduit 26 is sealed within the outlet 34 in the same manner as theconduit is sealed within the stem 24. The outer end of the outlet 34 isthreaded to receive a correspondingly threaded cap 37 through which theconduit 26 passes into the outlet. The outlet 34 and cap 37 arechamfered as at 38 and 39, respectively, to receive a ring seal 40 andtightly seal the conduit within the outlet 34 when the cap 37 isthreaded onto the outlet 34. Therefore, when the tube is unobstructed,the confined fluid 36 within the chamber 25 is free to expand into thedoughnut-shaped tube 21.

The opening in a tip 41 of the conduit 26 extending within the outlet 34is of a substantially reduced diameter and is sealed by a plug 42 ofheat-disruptable material to allow remote control of the inflation lofthe sealing tube, as hereinafter described. The tip 41 is formed in anysuitable manner such as swaging.

The second outlet 35 accommodates a discharge conduit 43 whichcommunicates with the well above the chamber. The conduit 43 is sealedin place in the same manner as the conduit 26 by a ring seal 44 forcedinto position by a cap 45 which threads onto the outlet 35.

The opening in a tip 46 of the second conduit 43 is also reduced indiameter and plugged with a heat-disruptable material 47 to effect aremote control of the deflation of the sealing tube, as hereinafterdescribed.

A heating coil 48 is wound around and in close proximity to the firstoutlet 34 and similarly a heating coil 49 is wound around and in closeproximity to the second outlet 35. When each of the heating coils 48 and49 is energized, the associated heat-disruptable plugs 42 and 47 areheated and are disrupted to open the respective conduit.

A heat-disruptable plug is defined as one that allows an opening of thepassage in response to a predetermined rise in temperature either as aresult of fusion, combustion or disintegration of the plug or as aresult of a loosening of the plug from the tube so as to allow thepressure of the confined gas to force or push the plug from its closingposition. For example, a suitable plug is a low temperature solderdisposed within the reduced openings of the conduits 26 and 43. Thesolder is fused to the walls of the tubes and forms a positive sealingof the tubes. When the solder is heated, it softens or melts and allowsthe pressure of the confined gas to push or blow it into the largerdiameter portion of its respective tube.

The electric leads 50 and 51 for the coils are disposed within a shield52 which also houses the main motor power line 6.

As shown in the drawing, the coils have a common return lead 53 which ispermanently connected to the line 54 of the supply lines 8. Each of thecoils 48 and 49 also has an associated lead 55 and 56 which is connectedto a contact 57 and 58, respectively, of an associated switch 59. Theswitch 59 is connected to a line 60 of the supply lines 8. To energizethe coil 48 the switch 59 is closed into engagement with the contact 57and to energize the coil 49, the switch 59 is closed into engagementwith the contact 58.

The operation of the above described embodiment of the invention is asfollows:

The submersible motor-pump unit is lowered into the well and secured ata predetermined elevation by the cable 9. The switch 59 is then closedinto engagement with the contact 57 and the heating coil 48 isenergized. The heat-disruptable material 42 is disrupted and opens thepassage to the sealing tube 21. The confined fluid 36 expands andinfiates the sealing tube 21 and thereby seals the motor-pump unit tothe well casing 4, as shown in Figure 1. During operation, the pump 2forces water into the well casing above it. The sealing tube 21 preventsthe pumped water from returning to its original level. The check valvewithin the pump, not shown in the drawing, serves to prevent the pumpedwater from returning from the casing to its original level when the pumpis not operating. Therefore, the well casing 4 above the seal 21 servesas the conventional tubing from the pump to the discharge pipe 18.

When the motor-pump unit is to be removed from the well, the heatingcoil 49 is energized by closing the switch 59 into engagement withcontacts 58. The heat generated by the coil 49 disrupts material 47 andthereby opens the outlet passage 35. The confined fluid 36 escapes fromthe chamber 25 and the sealing tube 21, allowing the collapse of thesealing tube and removal of the motor-pump unit.

To re-use the apparatus, the tubes 26 and 43 are again sealed. and thegas 36 is replaced whereby the apparatus is again adapted to seal amotor-pump unit within a well casing.

Any suitable means may be employed to replace the gas 36 such as afitting which permits the filling of the chamber through the dischargepassage 35 and then permits the sealing of the conduit 43 within thedischarge passage 35.

Although` the seal is described as applied to a pump having a checkvalve, the seal is equally applicable to a pump without such a valve. Ifa check valve is not used, then the well liquid must first fill the wellcasing at each pumping before water can be drawn from the well.

The presently disclosed seal is particularly adapted for an inaccessiblydisposed seal which is to remain intact for a number of years. This isbecause no mechanically actuated mechanism is employed in the structureof the controlled seal. Although a mechanical valve or similar seal issuitable for general application, when a seal is to be opened only atsome remote future time, there is a substantial danger that themechanical variety seal will leak prior to that time or that it willfreeze shut. With a relatively inaccessible seal, it is particularlyimportant that the preceding be prevented.

The present invention provides a positive acting and low-costconstruction for a remotely controlled seal.

Various modes of carrying out the invention are contemplated as beingwithin the scope of the following claims particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

I claim:

l. Sealing apparatus for closing the passage between a submersiblemotor-pump unit and a well casing, which comprises an expansible memberdisposed between the motor-pump unit and the well casing, a chamberdisposed adjacent to the motor-pump unit and having an outlet passageconnecting the chamber into communication with the expansible member,said chamber being adapted to hold a pressurized'fiuid therein, aheat-disruptable material disposed within said passage to close thepassage, an electrically energized heating element disposed adjacent theheat-disruptable material to effect a disruption of said material and aconsequent inflation of said expansible member, a source of currentconnected to the heating element to control the energization of theheating element, and control means for said source of current disposedat the upper end of the well casing to selectively energize said heatingelement.

2. Sealing apparatus for closing the passage between a motor-pump unitand a well casing, which comprises an expansible member disposed betweenthe motor-pump unit and the well casing, a chamber disposed adjacent tothe motor-pump unit and having an outlet passage connecting the chamberinto communication with the expansible member, said chamber beingadapted to conne a pressurized uid therein, a heat-disruptable materialdisposed within said passage to close the passage, an electrical heatingelement secured adjacent the heat-disruptable material to eiect anopening of the passage, a second outlet passage connecting the chamberand the well uid into communication, a heat-disruptable materialdisposed within the second outlet passage to close the second passage, asecond electrical heating element secured adjacent the heat-disruptablematerial in the second passage to eifect an opening of the secondpassage and :a consequent deflation of the expansible member, a sourceof current connected in circuit with the first and second namedelectrical heating elements, and control means for said source ofcurrent disposed at the upper end of the well casing to selectivelyenergize the rst and second named heating elements.

3. A control apparatus for closing the passage between a submersiblemotor-pump unit and a well casing by an inilatable member, whichcomprises a chamber -attached to the motor-pump unit and inserted intothe well casing with the motor-pump unit, a tube connected between thechamber and the inflatable member to provide a passage between thechamber and the inflatable member, a heatdisruptable plug closing thetube between the chamber and the inflatable member, a pressurized uidconined within the chamber under sucient pressure to elect an inflationof the inatable member upon opening the tube to thereby seal themotor-pump unit and the well casing, an electrical heating elementsecured adjacent the plug, and a remote manual control disposed adjacentthe upper end of the well casing and connecting the heating element incircuit with a source of power.

4. A remotely controlled sealing device for closing the passage betweena submersible motor-pump unit and a well casing by an expansibledoughnut-shaped member surrounding the motor-pump unit, which comprisesa chamber secured to the motor-pump unit and lowered into the wellcasing therewith, a pressurized uid conned within said chamber, a firsttube connected in communication with said expansible member and saidchamber to etect an ination of the member by said pressurized fluid, asecond tube communicating with the exterior of the chamber and thechamber to effect a deation of the eX- pansible member, aheat-disruptable plug in said rst tube, a heat-disruptable plug in saidsecond tube, an electrical heating means secured adjacent said first andsecond heat-disruptable plugs to rst effect an opening of said firsttube and an ination of the expansible member and to secondly effect anopening of said second tube and a deflation of the expansible member, asource of power, and manually operated means disposed adjacent the upperend of the well casing and connecting the source of power and theelectrical heating means to permit selective energization of the heatingmeans and consequent individual control of the opening of said firsttube and said second tube.

References Cited in the le of this patent UNITED STATES PATENTS2,207,001 Dillon Oct. 1l, 1937 2,245,144 Grith Jan. 27, 1940 2,269,189Downs` Jan. 6, 1942 2,458,270 Humason Jan. 4, 1949 2,702,993 Harris Mar.1, 1955

